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Biomedical subjects

M Lin

Publications and source records attributed to M Lin.

At least 271 records · Page 15Linked to original sources
PubMed1995

Development of the gonads in the triploid (ZZW and ZZZ) fowl, Gallus domesticus, and comparison with normal diploid males (ZZ) and females (ZW).

Gonadal development in fowls aged from 1 day to more than 4.5 years was studied in 63 ZZW and 16 ZZZ triploid crossbreds and compared with normal diploid males (ZZ) and females (ZW). In the ZZW fowl, the right gonad developed into a testis (although this occurred earlier in the ZZ genotype), and a structurally-abnormal excurrent duct system containing some malformed spermatids and spermatozoa was associated with the gonad of young adults. The left gonad was an ovotestes at hatching and no excurrent ducts were associated with it. The ovarian component was much less developed than that in the ZW genotype-it started to degenerate by 1 week of age, and most of the oocytes had disappeared by about 3 weeks of age. The seminiferous tubules developed in the medullary region, but only abnormal spermatozoa were produced. Leukocytes infiltrated both gonads at about 9 months of age and the seminiferous epithelium had degenerated in most fowls over 1 year old. In ZZZ fowl, gonadal and excurrent duct development was normal, but occurred earlier than in the ZZ genotype. However, meiosis and spermiogenesis were abnormal and malformed spermatozoa were produced. The heads of spermatozoa from the ducts deferens were about 1.4-times longer in the ZZZ genotype than in the ZZ genotype, indicating that the former may be producing some diploid spermatozoa.

Animals↗
PubMed1995

Inhibition of collagenase type I expression by psoralen antisense oligonucleotides in dermal fibroblasts.

Type I collagenase plays an important role in both tumor metastasis and the remodeling of connective tissue in normal human skin, during wound healing, for example, and may participate in the pathophysiology of some dermatological diseases such as skin cancer and a chronic blistering disease, recessive dystrophic epidermolysis bullosa. In an effort specifically to inhibit collagenase expression, we have designed phosphorothioate antisense oligonucleotides, linked at the 5' ends with photoreactive 4'-(hydroxyethoxymethyl)-4,5',8-trimethyl-psoralen (HMT), and directed them against the 5' end of the collagenase mRNA. Two antisense-HMT molecules targeting a region overlapping the initiation codon were compared. Only one contained the HMT moiety targeting a 5'TpA on its complementary sense strand, and we observed greater than 50-fold improvement on the cross-linking of this antisense oligonucleotide to its target sequence after ultraviolet A (UVA) irradiation. Likewise, sequence complementary to the 5'TpA target was also required to demonstrate specific inhibition of in vitro translation of collagenase mRNA. Tissue culture experiments, conducted by incubation of collagenase-specific antisense-HMT oligonucleotides with fibroblasts in monolayer or in 3-dimensional dermal equivalents, showed lowered collagenase levels 24 h after UVA irradiation as compared to controls. Initial screening of antisense oligomers for specific hybridization and photo-cross-linking is a useful step in the design of antisense oligonucleotides, and allowed us to design an HMT-linked antisense phosphorothioate oligonucleotide that specifically inhibits the expression of fibroblastic collagenase.

Base Sequence↗
PubMed1995

Differences in colorectal cancer between China and Japan: a clinical and histological study of two groups of cases.

It is well known that most tumours are attributed to life style, especially the tumours of the digestive system. Clinical and histopathological investigation of tumours in different human groups and societies, and analysis of the variations will provide evidence for this, and is one of the approaches to study carcinogens. Clinical data obtained from 391 patients with colorectal cancer at the Sakai Municipal Hospital, Japan, and Shanghai Jinshan Hospital and Cancer Hospital, China, from 1987 to 1992, included the sex, age and tumour subsite. Sections of histological specimens were also retrieved. The results were compared between two countries. The average age of patients with colorectal cancer in Shanghai was 8.5 years less than in the Sakai group. The age peak of the former was 51-60, and in the latter, 61-70 years. The most frequent site of the cancer in the Shanghai group was the rectum, contrasting with the higher percentage of sigmoid colon cancer in Sakai group. There was also a significant difference in histological subtype of the cancer between the two groups. Mucinous adenocarcinoma was notably more common in the Shanghai group than in the Sakai group, and the high frequency was mainly in the colon. All of the variations were suggested to be attributable to differing socioeconomic circumstances and lifestyle, especially the dietary habits of the countries.

Adult↗
PubMed1995

Neonatal alloimmune thrombocytopenia in Taiwan due to an antibody against a labile component of HPA-3a (Baka).

We report on two siblings who developed severe neonatal alloimmune thrombocytopenia (NAIT) due to an alloantibody against a labile component or components of the HPA-3a (Baka) antigen. The antibody reacted only with fresh, unfixed platelets by the solid-phase red cell adherence test, immunofluorescence test and mixed passive haemagglutination test. In the latter method, weakly fixed platelets also gave a weak positive reaction. Monoclonal-antibody-specific immobilization of platelet antigens and immunoblotting tests gave negative results. Our findings may possibly help to explain why in some cases of NAIT no platelet-specific antibody is demonstrable in tests with fixed or solubilized platelets.

Antibodies, Monoclonal↗
PubMed1995

The Le(a) antigen and neonatal hyperbilirubinemia in Taiwan.

Neonatal jaundice is known to be more severe in Taiwanese infants than in Caucasian infants. Although ABO fetomaternal incompatibility and glucose-6-phosphate dehydrogenase deficiency have been shown to play a role in the etiology of neonatal jaundice in some Taiwanese infants, the etiology in the majority of cases is unknown. In this study we found that in Taiwanese newborn infants, the red cell Le(a) antigen appeared later in infants who were jaundiced (peak serum bilirubin levels of > 12 mg/dl during the first week of life) than in infants who were not. However, the Leb antigen, and hence the transferase encoded by the Se and Se(w) genes, did not appear to be similarly involved in the etiology of physiological jaundice. Thus it would appear that the Le gene-specified transferase is less active or has a delayed function, in jaundiced infants. The relationship between the Le gene-specified transferase and bilirubin has yet to be established.

Asian People↗
PubMed1995

Roles of oxidative stress in activation of Kupffer and Ito cells in liver fibrogenesis.

An increasing body of experimental evidence is emerging to incriminate oxidative stress as a pivotal signal for liver fibrogenesis. This paper reviews the results from our studies testing this hypothesis. In the rat model of alcoholic liver disease, the importance of oxidative stress was supported by marked accentuation of liver fibrosis by dietary supplementation of iron, a pro-oxidant, and the significant correlation of the liver malondialdehyde (MDA) and 4-hydroxynonenal (4HNE) levels with the hepatic collagen accumulation. Both MDA and 4HNE adduct epitopes were detected intensely and diffusely in close association with collagen deposition. The direct cause and effect relationship between MDA/4HNE and Ito cell stimulation was indicated by the demonstration of Ito cell collagen gene induction by these aldehydes in culture. In primary cultures of rat Kupffer cells (KC), addition of antioxidants such as alpha-tocopherol acetate and succinate suppressed mRNA expression and the release of interleukin (IL)-6 and tumour necrosis factor alpha (TNF alpha). In rats with biliary fibrosis, an increase in the liver MDA level was accompanied by enhanced mRNA expression of procollagen alpha 1(I) and transforming growth factor beta 1 in Ito cells; and that of TNF alpha and IL-6 in KC. Furthermore, the gel shift assay of KC nuclear extracts showed enhanced NF-kB DNA binding activity. These results support the proposal that enhanced oxidative stress constitutes an important signal for activation of Kupffer and Ito cells in experimental liver fibrogenesis.

Aldehydes↗
PubMed1995

Natriuretic peptides inhibit angiotensin II-induced proliferation of rat cardiac fibroblasts by blocking endothelin-1 gene expression.

The present study was aimed to test the role of endothelin-1 (ET-1) as a possible autocrine/paracrine growth factor for cardiac fibroblasts, and to examine its interaction with cardiac natriuretic hormones. Expression of preproET-1 (ppET-1) mRNA by cultured cardiac fibroblasts from neonatal rats was demonstrated by Northern blot analysis using cDNA for rat ppET-1 as a probe. Angiotensin II (ANG II) and ET-1 transiently (30 min) increased steady-state ppET-1 mRNA levels in cardiac fibroblasts. Both ET-1 and ANG II significantly stimulated [3H] thymidine incorporation into cardiac fibroblasts, whose effects were dose-dependently inhibited by an ETA receptor antagonist (BQ123), BQ123 also inhibited both ET-1- and ANG II-induced ppET-1 mRNA expression. Both atrial and brain natriuretic peptides (ANP, BNP), which activate particulate guanylate cyclase, inhibited ppET-1 mRNA expression and [3H]thymidine incorporation stimulated by ANG II and ET-1. Sodium nitroprusside, a soluble guanylate cyclase activator, and 8-bromocyclic GMP, a membrane-permeable cGMP derivative, similarly inhibited ppET-1 mRNA expression and [3H]-thymidine incorporation. BNP was more potent than ANP to inhibit ANG II- and ET-1-stimulated DNA synthesis, whereas BNP and ANP were almost equipotent in stimulating cGMP generation in cardiac fibroblasts. Our data demonstrated that ANG II and ET-1 upregulate ET-1 gene expression in rat cardiac fibroblasts partly via cyclic GMP-dependent mechanism, and that natriuretic peptides inhibit ANG II-stimulated proliferation of cardiac fibroblasts, possibly by inhibiting ET-1 gene expression. Our data suggest the possible role of endogenous ET-1 as an autocrine/paracrine growth factor for cardiac fibroblasts and its close interaction with natriuretic peptides in the regulation of cardiac fibrosis.

Angiotensin II↗
PubMed1995

Left ventricular geometry and cardiac function in mild to moderate essential hypertension.

To elucidate left ventricular (LV) cardiac structure and function in patients with mild to moderate essential hypertension, we studied the relationship between LV geometry and function. We evaluated LV diastolic and systolic functions by M-mode echocardiography in 91 age-matched normotensive control subjects (NT) and 124 patients with essential hypertension. Hypertensive patients were divided into two groups based on the WHO stage classification: WHO I (n = 76) and WHO II (n = 48). Patients in WHO I and WHO II were further categorized according to the relative wall thickness as normal left ventricle (n = 47), concentric remodeling (n = 29), concentric hypertrophy (n = 25), and eccentric hypertrophy (n = 23). LV diastolic function was significantly decreased in the hypertensive groups compared to NT. There was no significant difference in LV systolic performance among NT, WHO I and WHO II. LV contractility was significantly increased in WHO I compared to NT. In respect to ventricular geometric pattern, LV diastolic function was significantly decreased in both the concentric hypertrophy and eccentric hypertrophy groups. LV systolic dysfunction was noted only in the eccentric hypertrophy group. In conclusion, patients with concentric remodeling had normal systolic and diastolic functions. LV diastolic function was impaired in both the concentric and eccentric hypertrophy groups due to an increase in LVMi. Moreover, LV systolic impairment was noted in the eccentric hypertrophy group due to an inappropriate compensation to LV systolic load.

Adult↗
PubMed1995

Reappraisal of continuous positive airway pressure therapy in acute cardiogenic pulmonary edema. Short-term results and long-term follow-up.

To investigate whether serial incremental continuous positive airway pressure (CPAP) has any short-term or long-term advantages over face-mask oxygen therapy by way of intrapulmonary shunt reduction, 100 patients admitted to the coronary care unit for the treatment of acute cardiogenic pulmonary edema were studied. All patients received Swan-Ganz catheterization. Hemodynamic and pulmonary function parameters were recorded over the next 6 h, and the patients were followed until hospital discharge. All survivors received regular follow-up at 1-month intervals in the outpatient clinic. During the first-stage investigation period (3 h) PaO2 in the CPAP group showed a significant increase, whereas the intrapulmonary shunt and alveolar-arterial oxygen tension gradient (P[A-a]O2) was significantly reduced (p < 0.005). The CPAP group had significantly lower rate-pressure product and higher stroke volume index compared with the control group. The therapeutic failure rate over 6 h was 24% in the CPAP group and 50% in the control group (p < 0.01). The CPAP group had a significantly lower incidence of tracheal intubation and ventilator therapy than the control group; however, there was no significant difference in short-term mortality and hospital stay between the two groups. In conclusion, although study size was not large enough to demonstrate a difference in mortality, CPAP therapy resulted in physiologic cardiovascular and pulmonary function improvement and significantly reduced the need for intubation; however, it did not decrease mortality in patients with acute cardiogenic pulmonary edema, and a much larger study is needed to investigate this possibility.

Acute Disease↗
PubMed1995

Electron microscopy of the seminiferous epithelium in the triploid (ZZZ and ZZW) fowl, Gallus domesticus.

The ultrastructure of cells of the seminiferous epithelium is described in both triploid ZZZ and ZZW fowls, especially cytological aberrations influencing the development of morphologically abnormal spermatids and spermatozoa. Mitotic divisions in triploid fowls are similar to those in diploid fowls, but meiosis in both the ZZZ and ZZW triploid fowl is abnormal and many defective gametes are produced. The majority of spermatids have structural abnormalities and this is attributed to the aneuploidy expected from meiotic chromosome pairing in a triploid. Some spermatids were observed to possess an irregularly shaped head, 2 centriolar complexes, 2 acrosomes and 2 tails and this type differentiated into large-headed spermatoza. Such spermatids and spermatozoa are suggested to be near diploid due to their large nuclear size and 2 sets of organelles. Other spermatids, observed with only 1 centriolar complex, 1 acrosome and 1 tail, are suggested to be near haploid. Differentiation of these spermatids is similar to the process observed in diploid fowls except that there is a high percentage of abnormally shaped heads. The fact that morphologically normal spermatozoa were rare is consistent with the expectation that very few spermatozoa would be exactly haploid. In both ZZZ and ZZW triploid fowls, triple pairing of chromosomes is observed in synaptonemal complexes (SC) during meiosis and recombination nodules are distributed at random in the central regions of the triple pairing SC. In ZZW triploid fowls gamete formation is more severely affected than in ZZZ triploid fowls and it is suggested that many of the degenerative changes occurring in ZZW fowls could be attributed to those spermatids that possess a W sex chromosome, since normal male fowls are the homogametic sex (ZZ) and normal spermatids and spermatozoa contain only a Z sex chromosome.

Animals↗
PubMed1995

Effects of the benzodiazepine inverse agonist RO19-4603 on the maintenance of tolerance to a single dose of ethanol.

The time course of the novel benzodiazepine inverse agonist, RO19--4603 (0.075 or 0.150 mg/kg) in antagonizing the depressant effects of ethanol (EtOH) (0.50, 1.0 and 1.5 g/kg) and the development of tolerance on locomotor behaviors (e.g., ambulatory count, total distance and stereotypy count) were investigated in Sprague-Dawley rats given EtOH injections spaced at 24-hr intervals. A single dose of RO19--4603 prevented the development of tolerance to the 0.50- and 1.0-g/kg EtOH doses 24-hr post-RO19--4603 administration on most locomotor behaviors. On Day 1, the 0.150-mg/kg RO19--4603 dose prevented the reduction of motor behaviors after the 1.0- and 1.5-g/kg EtOH doses, whereas the 0.075-mg/kg RO19--4603 dose prevented the reduction of motor behaviors only after the 1.5-g/kg EtOH dose. The 0.075- and 0.150-mg/kg RO19--4603 doses also prevented the EtOH-induced reduction of motor behaviors after the 1.5-g/kg EtOH dose 24-hr post-RO19--4603 administration. RO19--4603 was without effect on activity when given alone. These data suggest that the motor impairing effects of EtOH and the development of tolerance to them may involve gamma-aminobutyric acidA-benzodiazepine receptor mechanisms that when occupied, even briefly by certain benzodiazepine inverse agonists, produce long-lasting effects on locomotion and tolerance.

Animals↗
PubMed1995

[High yield techniques for bupleurum falcatum L].

The growth of plants may be controlled by clipping the aerial part. This may increase the yield of Bupleurum falcatum. Different methods of cultivation may result in different outputs of crude drugs. Compared with land plotting, deep ploughing and high ridging may increase the root weight of one-year-old plant by 28% and 50% respectively.

Plants, Medicinal↗
PubMed1995

[The use of measuring serum soluble IL-2 receptor levels in cyclosporine-A treated lupus nephritis].

Twenty-one patients with Lupus Nephritis (LN) were treated with cyclosporine-A (CsA) for three months. Serum soluble interleukin-2 receptors (SIL-2R) were measured before and after treatment and correlated prospectively with serologic findings of LN activity. The patients had significantly higher IL-2R level before treatment (during LN flare) than after treatment (disease remission). A significant positive correlation was present between serum SIL-2R and proteinuria, and ANA as well, whereas the SIL-2R levels in LN patients were inversely correlated with serum levels of C3 and CH50. These observations suggest that serum SIL-2R level is an useful marker of disease activity in LN and may serve as a helpful adjunct in the management of this disorder.

Adult↗
PubMed1995

[A study on behavioural characteristics of staying on the mountain and its relationship with malaria infection in Li and Miao minorities in Hainan Province].

A study of sociology combined with epidemiology was conducted in Li Minority's two villages and Miao Minority's two villages nearby the foot of mountain in a historically malaria hyperendemic area, Nanqiao Township of Wanning County in August, 1993. The results showed that malaria infection was closely correlated to the behaviour of staying overnight on the mountain of Li and Miao Minorities during farming seasons. Most of Li people stayed overnight on the mountain for planting areca were adults, accounting for 21.6% of the whole population, the duration of stay was about half a year; Miao people stayed overnight on the mountain planting and harvesting upland rice, always with their family member, so the percentage of people who had stayed on the mountain was as high as 82.1%, the duration of stay was about one and half a month. Blood smear examination showed that the malaria parasite rates in both Li and Miao villages were 11.1% and 24.1%, respectively, the positive rate of P. falciparum was 1.0% and 9.1%, respectively, the positive rate of IFA (titer >or= 1 : 40) was 31.2% and 46.5%, respectively. It is indicated that both the rate of parasitaemia and the P. falciparum infection were much higher in Miao Minority than those in Li Minority (P < 0.001). A cohort analysis showed that the malaria parasite rate of population who having not stayed, having ever stayed and being stayed on the mountain was 6.5%, 27.4% and 42.1%, respectively, of them the rate of P. falciparum infection was 0.5%, 8.8% and 18.4%, respectively. The results suggest that malaria acquired from mountainous forest referring to "up-mountain infection" is a major source of malaria infection and a significant risk factor in determining the prevalence of malaria (especially falciparum malaria) in Hainan Province. This behavioural risk factor has become the main obstacle for malaria control in Hainan Province. Therefore, controlling "up-mountain infection" and adopting appropriate anti-malaria measures to protect the risk population who have to work and stay on the mountain should be strengthened in the malaria control program.

China↗
PubMed1995

Effect of age on left ventricular geometric patterns in hypertensive patients.

OBJECTIVES: To investigate the effect of age on left ventricular structure and geometry in hypertensive patients, we studied the relationship between age and echocardiographic variables in patients with uncomplicated essential hypertension. PATIENTS AND METHODS: We divided 168 patients with hypertension into three groups according to age: young (<40 years), middle-aged (40-59 years) and an elderly group (> or = 60 years). They were further categorized according to relative wall thickness and the left ventricular mass index. We then evaluated the prevalence of left ventricular geometric patterns in these patients according to age. RESULTS: The left ventricular end-diastolic dimension decreased with age, both in normotensive control subjects and in hypertensive patients. The magnitude of this decrease was similar for both. The relative wall thickness and left ventricular mass index were greater in the hypertensive patients than in the normotensive control subjects, and these increased with age both in the controls and the hypertensives. The differences between normotensives and hypertensives in these variables remained unchanged with age. The prevalence of a normal left ventricle (normal relative wall thickness and left ventricular mass index) in the hypertensive patients decreased with age. Conversely, the prevalence of concentric remodeling (increased relative wall thickness with normal left ventricular mass index) and concentric hypertrophy (increased relative wall thickness and left ventricular mass index) increased with age. CONCLUSIONS: These results demonstrate that age significantly affects left ventricular structure both in normotensive control subjects and in hypertensive patients. Thus, the differences in left ventricular geometric patterns with age may have important implications in assessing left ventricular structure and geometric patterns in hypertensive patients.

Adult↗